Søren Laurentius Nielsen

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Kelps, seaweeds and seagrasses provide important ecosystem services in coastal areas, and loss of these macrophytes is a global concern. Recent surveys have documented severe declines in populations of the dominant kelp species, Saccharina latissima, along the south coast of Norway. S. latissima is a cold-temperate species, and increasing seawater(More)
We tested the existence of general patterns in the photosynthetic metabolism of oxygen-evolving organisms, based on a compilation of data for 315 species ranging from cyanobacteria to tree leaves. We used thickness and chlorophyll a concentration of the photosynthetic structure (cell, thallus, leaf) to scale differences in photosynthetic metabolism among(More)
1. This paper focuses on the marine foundation eelgrass species, Zostera marina, along a gradient from the northern Baltic Sea to the north-east Atlantic. This vast region supports a minimum of 1480 km eelgrass (maximum >2100 km), which corresponds to more than four times the previously quantified area of eelgrass in
We have studied the effect of light acclimation on photosynthetic responses and growth during Cu2+ exposure (0-0.84 microM) in the brown seaweed Fucus serratus. Measurements of chlorophyll fluorescence parameters showed that Cu2+ exposure amplified ETR, reduced the chlorophyll content at the cellular level and that there was no effect of light adaptation on(More)
Activated carboxylase activities of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), as well as photosynthetic rates were measured for 42 species of freshwater and marine macrophytes. While the carboxylase activity varied greatly among the species investigated (0.2–12.5 μmol CO2 mg−1 chlorophyll min−1), the submersed freshwater plants showed(More)
The cryptophyte Rhodomonas salina is widely used as feed for copepod cultures. However, culturing conditions to obtain high-quality algae have not yet been efficiently optimized. Therefore, we aimed to develop a cultivation protocol for R. salina to optimize its nutritional value and provide technical recommendations for later large-scale production in(More)
We measured PAR-saturated CO2 exchange rate (CER), and leaf N, P and chlorophyll (Chl) concentrations in 21 plant species, selected to encompass as broad a range in specific leaf area (SLA) as possible, and encompassing non-succulent C3 as well as succulent CAM plants. We worked with plants growing under uniform conditions in the facilities of a biological(More)
The relationship between light acclimation and Cu(2+) tolerance was studied in two populations of Fucus serratus known to be naturally non-tolerant and tolerant to Cu(2+). Acclimation to high irradiances increased the photosynthetic tolerance to Cu(2+). The xanthophyll cycle was apparently not involved in protecting the photosynthetic apparatus against(More)
Fourteen temperate, submerged macrophytes were cultivated in the laboratory at high DIC levels (3.3–3.8 mM), 10.4–14.4 mol photons (PAR) m-2 d-1 and 15°C. Photosynthesis at photosaturation ranged between 0.59 and 17.98 mg O2 g-1 DW h-1 at ambient pH (8.3) and were markedly higher between 1.76 and 47.11 mg O2 g-1 DW h-1 at pH 6.5 under elevated CO2(More)
The purpose of this study was to clarify effects of anthocyanins on photosynthesis and photoinhibition in green and red leaves of Oxalis triangularis. Gas analysis indicated that green plants had the highest apparent quantum yield for CO2 assimilation [0.051 vs. 0.031 μmol(CO2) μmol−1(photon)] and the highest maximum photosynthesis [10.07 vs. 7.24 μmol(CO2)(More)